A video signal source for providing a composite video signal (for example, a video recorder, a camera or a character generator) can be connected to the so-called "SCART" input connector or socket of a television receiver. The composite video signal (hereinafter "CSCC") of such a transmitter is conventionally applied to pin 20 of the SCART socket. On the other hand, there are also video signal sources which on the one hand provide a luminance (here in after, SCC) signal and on the other hand provide a modulated color subcarrier C at separate outputs. This signal transmission format is used with so-called "Super VHS" (S-VHS) and has the advantage that no cross-talk occurs between the luminance signal and the color subcarrier. Advantageously, in apparatus utilizing S-VHS input signals, the conventional color subcarrier trap in the path of the luminance signal is not required. With such a signal source, the luminance (Y or "SCC") signal is fed to the pin 20 of the "SCART socket of the apparatus without the color subcarrier and the modulated color subcarrier (C) is fed to the pin 15 of the SCART socket.
The two mentioned signal types (e.g., composite and S-VHS video) require different processing within the television device. Therefore, it is known to provide the device with a manual change-over switch with which a suitable change-over is possible, for example, between the composite video signal format and the separated video signal format (e.g., between VHS and S-VHS sources, for example). Thus, this change-over requires an additional manipulation or, stated another way, a change in the signal processing in the television apparatus. As well as that, there is a danger that with the presence of a S-VHS signal reproduction is performed in black and white follows although in reality a color television signal is present.
Also, a circuit is known (e.g., from EP-A2- 0 309 891) in which a changeover switch couples the input of the color decoder, in its neutral position, with pin 20 via a color sub-carrier filter and, in the second position, with pin 15. A switching voltage generated in the color decoder and indicating the presence of a color sub-carrier switches, when the color sub-carrier is present at pin 20, the changeover switch to its neutral position and, in the case there is no color sub-carrier at pin 20, to the second position. It is hereby attained that when the color sub-carrier is present at pin 20, i.e., a CSCC signal is present, only this signal is being evaluated and when no color sub-carrier is present at pin 20 the color channel is switched to pin 15. The latter is required in the known circuit because in that case the luminance signal Y at pin 20 and the color sub-carrier at pin 15 are provided separately.